The present invention relates to a method for automatic separation of foremilk and/or milk not suitable for consumption from the milk line system of a milking plant.
The invention also relates to an apparatus for cab out said method of separation, comprising means for separating and receiving a controlled quantity of milk.
The first phase of milking is normally referred to as the premilking phase and one essential step in the milking process for lactating animals is the performance of a proper premilking phase. It is well known that the drops of milk leaving the teat may be contaminated due to contamination on the outside of the teat or in the teat orifice, the teat canal or teat cistern and therefore the first drops are preferably discarded.
During said premilking phase it is normally desirable that the entire quantity of milk contained in the teat is extracted. This is primarily due to the requirement of checking tat the milk is suitable for consumption and does not include any traces of mastitis or contamination which for natal reasons are more likely to be present in the milk stored in the teat than in the milk from the udder cistern. Moreover, even though the teat normally is cleaned before the premilking takes place, it may occur that residues of dirt are present in the opening of the teat canal. At the same time, one does not wish to extract more milk during premilking than is absolutely necessary, since this milk is normally discarded off and therefore represents a cost.
Form ADD 261 300 is previously known a method and an apparatus for milking, comprising premilking and feeding of the foremilk via a central unit and a specific milk tube to a device with sensors for determining whether the milk is approved for entrance into the milk line system. An early diagnosis on actors depending on cow health can be made as well. After a test result concerning the foremilk-sample has been obtained, and the mil-quality has been approved, the apparatus is switched to a main milking phase. This is accomplished by manoeuvering a valve, by means of which the passage between the central unit and a regular long milk tube is opened and the passage to the specific milk tube is closed. The milk now flows via the long milk tube into the milk line system. When the test result reveals that the milk quality is inadequate, the valve remains in its position for sampling of foremilk and the milk is fed via the specific milk tube and a combination of valves into a milk line for non-approved milk. However, there are no references to milk sampling carried out for making an analysis of each teat or each add quarter.
From EP-A-0 277 396 is previously known a method for milking, comprising the use of a four-way valve connected to a conduit or short milk tube on each teatcup, by means of which valve milk and washing agent can be carried to different lines. In one described method a milk quality meter is applied, which is arranged on the conduit and measures the conductivity of milk or washing agent, as a result of which a regulating member can determine into which position a control member must actuate the four-way valve. The regulating member determines on the basis of the milk quality measured, at which precise moment the control member must switch over the four-way valve. If a teat of a cow is infected, a milk quality meter can be incorporated, which in addition to measuring the difference between milk and washing agent also measures the difference between milk suitable and milk not suitable for consumption. Upon proper regulation of the four-way valve it is possible to discharge milk suitable for consumption by one line and milk not suitable for consumption by a different line.
The above described methods and apparatuses have the disadvantage that it takes time to get an approval of the milk quality, which may result in that approved milk is lost into the milk line for non-approved milk. Also it is disadvantageous that the foremilk-sample can be diluted with ordinary milk which may start flowing past the sensors during the milk analysis and gradually makes the sample less representative of the composition of the foremilk.
An object of the invention is to solve the described problems with regard to previously known apparatuses by providing an improved method and apparatus for
The problems are solved by method as initially defined comprising the following steps:
localizing at least one teat;
automatically approaching a milking means to said teat and having said means automatically performing the following steps:
stimulating the teat in order to induce milk letdown;
extraction of milk from each teat; characterized in that
a first amount of the extracted milk is separated from the main milk flow and discarded;
a second amount of the extracted milk is separated from the main milk flow and analyzed, the result of the analysis being used to control at least one valve device.
A corresponding apparatus as initially defined is characterized by a separating device for separating a first amount of extracted milk from the main milk flow and discarding it, means for separating and receiving a second amount of milk from the main milk flow, said receiving means being provided with sensing means for indication of the milk quality, said sensing means being associated with a control unit for control of the milking process. A milking system according to the invention is comprised of different management concepts which are known per se such as cow identification, measuring the milk yield, milk flow and milking time, by different sensors measure deviations in the milk composition and automatic attachment and removal of the cluster. It is desirable to create a more adapted milking system, a system which is adapted to the four individual udder quarters, as it is well known that each udder quarter has individual milk flow curves, individual milking times and flow rates. Therefore, in order to create an optimal milking situation consideration has to be given to each individual quarter.
According to the invention, it is therefore advantageous to arrange the premilking of each quarter in such a way, that the first drops of milk and a predetermined volume or weight is separated from the main milk flow in the beginning of the milking Further it is advantageous to ascertain that the entire quantity of milk contained in the teat of the udder quarter in question is extracted during said premilking. This can be achieved by a special arrangement in connection with each teatcup for collecting, and analyzing said milk volume exclusive of the first drops of milk from said teat.